Theft preventing device



in a'plurality of rows.

Patented Sept. 8, 1942 UNETED STATES T NT OFFICE 1 Claim.

This invention relates to theft-preventing devices and has foi` its principal object the provision of a keyless device to prevent tampering with an electric circuit, usually one having a number of electrical elements therein.

A further object of the present invention is to provide a device for preventing the theft of an automobile by completing the ignition circuit thereof.

A still further object of the present invention is to provide a switch box by means of which an electric circuit can be completed and if the box is tampered with by someone not knowing the construction an alarm will be given while such unauthorized person is seeking to complete the circuit.

The usual method of preventing theft of an automobile is by having a key which closes the ignition circuit. The present invention contemplates the doing away with the key for the ignition circuit and providing in place of the usual switch a box or panel containing a number of holes, certain of which lead to contacts which, if properly made, will complete the circuit. The ignition circuit may be broken by removing any one of the two or more terminals of the connectors which complete the circuit. The invention will be described in connection with an automobile but it is readily understood by those skilled in the art that the electric circuit which is completed through this device may be of any type and may include -a single device such as a meter or a solenoid controlling a safe or other similar element.

In the drawing:

Figure 1 is a central section through a box employing my invention and showing the electrical circuit diagrammatically.

Figure 2 is a plan view of the box with the lid or cover omitted.

Figure 3 is a vertical section through one of the terminals in place in a modied Contact.

In Figure 1 the device is shown as a box III having therein a horizontal panel preferably composed of a series of materials, for example, a top layer Il of Bakelite, -a bottom layer I2 of wood, and an intermediate layer I4 of rubber. Through the panel thus formed there are openings I5 ranged in any formation but preferably Beneath two, four or more openings I secure terminals such as I'I which are electrically connected to the circuit to be protected. In Figure 1 the terminals I'I and I8l bridge one gap I9 in the electric circuit while the terminals 20 and 2| bridge a second gap 22 in the electric circuit which includes a battery or other source of current 23 and a plurality of elements each bearing the numeral 24 which in an automobile ignition system would include the distributor, the coil and spark plugs in the desired sequence. The gaps I9 and 22 are preferably so positioned that only one of the gaps is between two of the elements, thus preventing completion of the system by connecting the end terminals such as I8 and 2li.

For the authorized completion of the electric circuit I provide connectors such as Z, each having two terminals such as 2l and having for convenience the usual cylinder 28 through which the ccnnnecting wire may enter centrally but in the present instance I prefer that the wire shall enter from the side as shown in Figure 2 in order to minimize the space required above the panel. By inserting the two connectors as shown in the figures in the proper holes the circuit Will be completed but if any one of the four terminals is inserted in one of the other openings I5 the circuit will remain broken because there are only four connecting pieces. An unauthorized person attempting to make the proper connections would be faced with an almost impossible task because of the great number of possible permutations. For example, with only five holes yand with only one terminal there are ten permutations and with two conductors there are thirty possible arrangements, whereas with as few as eight holes, while there are only twenty-seven arrangements with one single conductor, with two conductors the number jumps to over four hundred, so that it is quite impossible with any reasonable number of openings and with only four terminals for the thief to make the proper selection.

While the panel could consist merely of one piece of wood such as I2, I prefer the assembly shown as the Bakelite top of the panel would not show wear appreciably to give a hint as to which one of the openings is used most and the rubber provides an extremely simple means for holding the terminals in place against jar. The openings .through the rubber sheet close when the terminal 21 is withdrawn. In automobiles the panel is used alone and would form a part of the dashboard. In this case the wires 32 lead-V ing from the contacts to the gaps would be made into a cable which would be armored as is frequent. If desired the contact instead of being a spring as at 20 may be an eyelet such as'38 having flanges 39 making a permanent comb-ination with the lower panel which as stated is pref-i erably made of wood but may be of any other insulating material.

As an auxiliary protection I provide an alarm circuit including the battery 23 and a device such as a horn or bell 3 I. The plunger 32 in the panel is urged into the position shown by means of a spring 33 and carries at its bottom a conducting disk 34 which makes contact with a plate 35 whenever the plunger 32 is in the position shown, thus completing the alarm circuit. The plunger 32 may be held down with the .thumb while an authorized person is arranging the connectors and it is normally held down by a projection 36 carried by the receptacle lid 31.

The operation is as follows: An authorized person lifts the lid 31 of the receptacle but promptly pushes down the plunger 32 to prevent the alarm system operating. He then places the two connectors in such position that the terminals will engage contacts 20 and 2l and l1 and IB, thus completing the ignition circuit. The lid is now lowered and this will hold the plunger depressed against the action of the spring 33, hence .the alarm will not sound. Due to the use of the side entrance wires the cover may t against the cylinders 28, thus economizing space.

What I claim is:

In an ignition circuit switch to prevent unauthorized use of an automobile, a switch box having a series of openings, four contacts in line with four of said openings, means joining the four contacts to form a circuit, having two brakes therein, one between the first two contacts and the other between the two additional contacts, said circuit being incomplete unless both breaks are independently bridged and a pair of iiexible connectors each having two terminals for manual insertion through the openings into electrical engagement with the contacts to complete said circuit the number of openings being more than double the number of contacts so as to present a high number of possible permutations, whereby when the ignition circuit loads such as distributor coil and spark plugs are located on the several sides of the two breaks and the four contacts are improperly joined by the two connectors the automobile cannot be operated.

CHARLES JACKSON. 

